As hardware makers continue to work on ways of making wide-scale quantum computing a reality, a startup out of Australia that is building software to help reduce noise and errors on quantum computing machines has raised a round of funding to fuel its U.S. expansion.

Q-CTRL is designing firmware for computers and other machines (such as quantum sensors) that perform quantum calculations to identify the potential for errors, making them more resistant and able to stay working for longer (the Q in its name is a reference to qubits, the basic building block of quantum computing). The startup is today announcing that it has raised $15 million, money that it plans to use to double its team (currently numbering 25) and set up shop on the West Coast, specifically Los Angeles.

This Series A is coming from a list of backers that speaks to the startup’s success to date in courting quantum hardware companies as customers. Led by Square Peg Capital — a prolific Australian VC that has backed homegrown startups like Bugcrowd and Canva, but also those further afield such as Stripe — it also includes new investor Sierra Ventures as well as Sequoia Capital, Main Sequence Ventures, and Horizons Ventures.

Q-CTRL’s customers are some of the bigger names in quantum computing and IT such as Rigetti, Bleximo and Accenture, among others. IBM — which earlier this year unveiled its first commercial quantum computer — singled it out last year for its work in advancing quantum technology.

The problem that Q-CTRL is aiming to address is basic but arguably critical to solving if quantum computing ever hopes to make the leap out of the lab and into wider use in the real world.

Quantum computers and other machines like quantum sensors, which are built on quantum physics architecture, are able to perform computations that go well beyond what can be done by normal computers today, with the applications for such technology including cryptography, biosciences, advanced geological exploration and much more. But quantum computing machines are known to be unstable, in part because of the fragility of the quantum state, which introduces a lot of noise and subsequent errors.

As Frederic pointed out recently, scientists are confident that this is ultimately a solvable issue. Q-CTRL is one of the hopefuls working on that, by providing a set of tools that runs on quantum machines, visualises noise and decoherence, and then deploys controls to “defeat” those errors.

Q-CTRL currently has four products it offers to the market, Black Opal, Boulder Opal, Open Controls and Devkit — aimed respectively at students/those exploring quantum computing, hardware makers, the research community, and end users/algorithm developers.

Q-CTRL was founded in 2017 by Michael Biercuk, a Professor of Quantum Physics & Quantum Technology at the University of Sydney and a Chief Investigator in the Australian Research Council Centre of Excellence for Engineered Quantum Systems, who studied in the U.S., with a PhD in physics from Harvard.

“Being at the vanguard of the birth of a new industry is extraordinary,” he said in a statement. “We’re also thrilled to be assembling one of the most impressive investor syndicates in quantum technology. Finding investors who understand and embrace both the promise and the challenge of building quantum computers is almost magical.”

Why choose Los Angeles for building out a U.S. presence, you might ask? Southern California, it turns out, has shaped up to be a key area for quantum research and development, with several of the universities in the region building out labs dedicated to the area, and companies like Lockheed Martin and Google also contributing to the ecosystem. This means a strong pipeline of talent and conversation in what is still a nascent area.

Given that it is still early days for quantum computing technology, that gives a lot of potential options to a company like Q-CTRL longer-term: the company might continue to build a business as it does today, selling its technology to a plethora of hardware makers and researchers in the field; or it might get snapped up by a specific hardware company to integrate Q-CTRL’s solutions more closely onto its machines (and keep them away from competitors). Or, it could make like a quantum particle and follow both of those paths at the same time.

“Q-CTRL impressed us with their strategy; by providing infrastructure software to improve quantum computers for R&D teams and end-users, they’re able to be a central player in bringing this technology to reality,” said Tushar Roy, a partner at Square Peg. “Their technology also has applications beyond quantum computing, including in quantum-based sensing, which is a rapidly-growing market. In Q-CTRL we found a rare combination of world-leading technical expertise with an understanding of customers, products and what it takes to build an impactful business.”